The gender pay gap has fallen below 10% for the first time, according to data published today by the Office for National Statistics (ONS).

Standing at 10.1% in April 2010, the gap between men's and women's median full-time hourly earnings excluding overtime was down to 9.1% in April 2011.

But the Annual Survey of Hours and Earnings (ASHE) low pay estimates for April 2011 show that there were 299,000 jobs paid below the national minimum wage held by people aged 16 and over, which constitutes 1.2% of all employee jobs in the UK labour market.

This is a result of women's earnings growing faster than men's. Men's earnings rose by 0.8% over the year (from £13.00 an hour in 2010 to £13.11 in 2011), while women's earnings rose by 1.9% - up from £11.69 an hour last year to £11.91 this year.

The gender pay gap for part-time employees was -5.6% in 2011, widening from -4.3% the year before. This means that part-time women are paid more than part-time men. The measure based on all employees fell from 19.8% in 2010 to 19.5% this year.

Other data in the ASHE show median gross weekly earnings for full-timers, at £501, were up by only 0.4% on the 2010 total of £499. Public sector workers saw a rise of only 0.3% (from £554 in 2010 to £556 this year) while in the private sector the increase was 0.8% (£473 a week in 2010, £476 in 2011).

But there was a widening in the gap between the highest and lowest paid employees: between 2010 and 2011, the hourly full-time earnings excluding overtime of those in the top decile grew by 1.8%, whereas those in the bottom decile saw an increase of only 0.1%.

London is region where employees had the highest full-time median gross weekly earnings, at £651, and the region with the lowest earnings was Northern Ireland at £451.

The district with the highest-paying jobs was the City of London (a median of £981 a week full-time) and the district with the lowest-paid jobs was Torridge (£333 a week full-time).

The highest paid occupation was directors and chief executives of major organisations (£1,956 a week full-time), while the lowest was school midday assistants (£233 a week full-time).